30yo with strange chest tightness suddenly over the past few weeks

Suddenly got chest tightness before christmas and it's been happening regularly since I started packing on the christmas pounds. At first I thought it was just absolutely diabolical heartburn. I used to fast and only eat one meal a day. Mostly, it happens in the morning after a solid dinner the night before, and getting in a cup of coffee to wake up.
Today was the worst. Had to go to the bathroom to put a cold towel over my face and breathe heavily over the bathroom sink which made the pain go away multiple times over the course of the 8hr shift. Not sure what the problem is, but I probably overate during the holidays and exacerbated an underlying problem. In the past I was 260lbs and got down to 150 back then. Also, I was 5'9 155lbs before the holidays and now I'm 162lbs.
Any advice would be appreciated but I should definitely see a doctor about this.

Update Jan 16:
I did check in on Saturday despite better advice, and have been admitted since then. I'm updating you because today they cleared me for a 4-hour release from care so I can come home and get some things for the remainder of the duration. So far I've been through numerous tests including but not limited to:
Multiple daily blood tests, generic and specifically looking for chemicals in the blood regarding heart and circulatory health
I've been hooked up to an ECG since Saturday, and symptoms have lessened to the point where it wasn't needed as of yesterday.
Two Endochardiograms
Radiation marker Myoview/MPI scan and stress test with persantine and dobut amine
And I am scheduled for a Radiation marker cardiac CT scan tomorrow, will follow up with results from that once I am out of the hospital.

Here's what the doctors have explained and the results so far:
Nutritionally, my general blood tests have shown no issues.
The doctor has noticed elevated lactate and troponin in my blood which would indicate damage to muscular tissue, with the troponin specifically indicating damage to the heart. Cholesterol levels normal.
When I checked in, My blood pressure and resting heart rate was in the upper areas of 175/110, and over 105 respectively
Confusingly, both endochardiograms, once when I checked in, and the other on tuesday, indicated no problems or damage
Same goes for the Myoview scan performed yesterday, it indicated no problems, and the chemical stress test which simulates 85% cardiovascular strain on the body had me at a peaked my heart rate of 91
As of today I still have high blood pressure, with the latest test reading 124/82, but my resting heart rate has dropped to the high 60s, low 70s, and since Sunday I haven't experienced any chest pain or pressure, even during the chemical stress test.

Still waiting for the CT scan tomorrow and the results following. If it gives clear results of no damage, I'll be fully discharged from the hospital with possible blood pressure medication prescription and followups with a dietitian as it's been made clear my diet has been fairly high in sodium, and I am a smoker. I've cut back quite a bit already with the goal of quitting altogether after this incident.
If the CT scan tomorrow shows damage, I'll possibly need a followup angiogram/stent and a longer stay.
I'm still feeling tired fairly easily, although I'm not experiencing shortness of breath as I'm still able to breathe normally.
The results still haven't been fully conclusive as to the cause, my father is sick with similar symptoms minus the heart issues and since my heart issues have dissipated I'm noticing more cold/flu-like symptoms.
At this point I have no answers as to the sole cause as it could be a combination of things. I'm asking for more followup tests for different areas of my body to find out.

TL;DR been admitted in hospital since saturday, doing a lot better, mostly good news from the doctors, and I'm sorry for making you guys wait for a response for so long. I appreciate you all.

Final update Jan 17:

The Cardiac CT scan from this morning came in in the afternoon. I'm diagnosed with moderate coronary artery disease, with a luckily low LAD CAC score of 3. According to the documentation, it is explained as "moderate coronary artery disease up to 1.7cm noncalcified plaque in LAD, moderate stenosis. I believe the measurement is of buildup along the length of the artery as 1.7cm is multiple times wider than the width of a coronary artery, and the low score is only due to the fact that the buildup hasn't calcified yet. They've provided me with a lot of in-depth information to turn things around and discharged me with contact information for a followup with a cardiac specialist. Despite being late, I'm glad I took your guys' advice and caught it at this point instead of delaying even further than I did.
With that said, it is one of the worst places to have buildup so I'll be making dietary and lifestyle changes, eliminating sodium from my diet for a long while, tapering off smoking with a nicotine inhaler until I've fully quit, and cutting out drinking entirely.
This stuff is no joke and I got extremely lucky in spite of my negligence. Thank you guys once again and I apologize if I offended anyone or made them worry.