I was prescribed doxycycline by the doctor for a misdiagnosed std...

I was prescribed doxycycline by the doctor for a misdiagnosed std, i took the 7 day regiment along with another antibiotic, while taking both antibiotics, i experienced major stomach gas and a complete loss of appetite....after the 7 days was up, i still did not feel quite right, so saw my doctor about 5 days later....he re-prescribed ONLY doxycycline....this time WITHOUT taking the other antibiotic, my gas was much less severe...however i have to FORCE myself to eat due to a complete loss of appetite...i want so bad to have an appetite back the thought of taking even one more of those pills repulses me....though the medication works quite well.....I also find that while taking doxycycline my eyes would burn from time to time....one pill left....and im gonna skip it.